| (19) |
 |
|
(11) |
EP 1 164 120 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
05.02.2003 Bulletin 2003/06 |
| (43) |
Date of publication A2: |
|
19.12.2001 Bulletin 2001/51 |
| (22) |
Date of filing: 12.06.2001 |
|
|
| (84) |
Designated Contracting States: |
|
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
|
Designated Extension States: |
|
AL LT LV MK RO SI |
| (30) |
Priority: |
12.06.2000 JP 2000175043
|
| (71) |
Applicant: Nippon Shokubai Co., Ltd. |
|
Osaka-shi, Osaka 541-0043 (JP) |
|
| (72) |
Inventor: |
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- Yunoki, Hiromi
Himeji-shi, Hyogo-ken (JP)
|
| (74) |
Representative: Cresswell, Thomas Anthony |
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J.A. KEMP & CO. 14 South Square Gray's Inn
London WC1R 5JJ
London WC1R 5JJ (GB) |
|
| |
|
| (54) |
A process for producing acrylic acid |
(57) A process of producing acrylic acid comprising vapor-phase catalytic oxidation of
acrolein-containing gas using a shell-and-tube type fixed bed reactor, said process
being characterized in that each of the reaction tubes contains catalyst in three
or more reaction zones in the axial direction, the catalyst in the first reaction
zone closest to the gas inlet having a higher activity than that of the catalyst in
the adjacent, second reaction zone and the catalyst in each of the subsequent reaction
zones having an activity level higher than that of the catalyst in the adjacent reaction
zone on the gas inlet side.